Air conditioning



L. M NEELY AIR CONDITIONING Jan. 1, 1952 2 SHEETS-SHEET 1 Filed Aug. 14, 1948 INVENTOR. M flfh Av H774/7/V') Patented Jan. 1, 1952 I 2,581,122 Am CONDITIONING Lowell McNeely, Evansville, Ind., assignor to Servel, Inc., New York, N. Y., a corporation of Delaware Application August 14, 1948, Serial No. 44,381

Claims. (Cl. 257-3) The present invention relates to air conditioning apparatus for cooling or heating the air in an enclosure and more particularly to an arrangement for simultaneously dehumidifying the air by cooling and reheating the dehumidified air.

The present invention is adapted for use with and constitutes an improvement in an air conditioning apparatus and controls of the type illustrated and described in United States Letters Patent to Sven W. E. Andersson, No. 2,486,908, issued November 1, 1949 and entitled Air Conditioning. The air conditioning apparatus illustrated in the said prior application comprises a heating system, a heat operated refrigeration system, a source of heating medium and a valve for directing heating medium from said source to either the refrigeration system or heating system, respectively. A selective control operates the valve to select the heating system or refrigeration system for operation and a thermostat responsive to the temperature of the ambient in the enclosure regulates the operation of the selected system.

An auxiliary control is also provided for adjusting the valve to simultaneously supply heat to both the refrigeration and heating systems to dehumidify the air by cooling and reheat the valve to obtain the desired nicety of division of.

heating medium between the heating and refrigeration systems. Also the control is quite complicated and the arrangement requires an additional motor to adjust the valve between heating and cooling positions.

One of the objects of the present invention is to provide a reheat arrangement in an air conditioning apparatus of the type indicated which insures a predetermined division of the heatin medium between the refrigeration and heating systems.

Another object is to provide an arrangement in an air conditioning apparatus of the type indicated for supplying heating medium to the heating system through one path to heat the air in an enclosure and through another path to reheat air dehumidifled by the refrigeration system.

Another object is to provide conduit means including a selective valve for directing steam to either the heating system or refrigeration system and a by-pass with a reheat control valve for delivering steam to the heating system simultaneously with its delivery to the refrigeration system.

2 Another object is to provide a reheat control valve in the form of a liquid trap in the by-pass conduit which utilizes condensate from the heating system to close the conduit.

Another object is to provide a drain from the liquid trap in the by-pass conduit together with means for closing the drain to fill the trap with condensate and close the conduit or open the drain to draw off condensate and open the conduit.

Another object is to provide a thermostat and humidistat connected for joint operation to open the drain when the temperature is below a predetermined value and the humidity is above a predetermined value.

Still another object is to provide a reheat control arrangement which is of relatively simple construction, economical to manufacture and dependable in operation.

These and other objects will become more apparent from the following description and drawings in which like reference characters denote like parts throughout the several views. It is to be understood, however, that the drawings are for the purpose of illustration only and do not limit the scope of the invention, reference being had for this purpose to the appended claims. In the drawings:

Fig. 1 is a diagrammatic view of an absorption refrigeration system incorporation the reheat arrangement of the present invention;

Fig. 2 is an enlarged view of the reheat control arrangement showing the liquid trap in the by-pass conduit filled with condensate to close the conduit, and I Fig. 3 is a view similar to Fig. 2 showing the drain open to draw off condensate and open the by-pass conduit.-

The air conditioning apparatus to which the present invention is shown applied is generally similar to that illustrated and described in U. S. Patent No. 2,486,908, referred to above. Sufllce it to state herein that the air conditioning apparatus comprises'a duct 4 for receivin air from the enclosure 5 to be conditioned and a duct 6 for delivering air to the enclosure. The air to be conditioned is circulated through the ducts I and 6 in the direction indicated by the arrows by means of an electric motor operated blower 1. As the air flows through the duct 4 it is conditioned by elements therein comprising a filter 8, a cooling element 9, a heating element In and humidifier H. The cooling element 9 constitutes the evaporator of a heat operated absorption refrigeration system while the heating element In constitutes the radiator of a heating system. Both the refrigeration system and heating system are selectively supplied with a suitable heating medium, such as steam, from any suitable source and as illustrated the source of steam is a boiler l2. The heating steam is directed to either the refrigeration system or the heating system by a diverter valve i3, later to be described in detail.

The heat operated refrigeration system preferably is of the type which operates in a partial vacuum and utilizes water as a refrigerant and a salt solution as an absorbent. The refrigeration system comprises a generator l4, a

condenser l5, evaporator 9, an absorber l6 and heat exchanger ll interconnected to provide a closed circuit. The generator l4 comprises a series of upright tubes l8 connected at their lower end to an inlet chamber IQ for absorption solution and connected at their upper ends to a separating chamber 20. Surrounding the tubes [8 is a jacket 2| providing a heating chamber 22 therebetween.

Steam is supplied from the boiler l2 to the heating chamber 22 of the generator through a steam main I2a, diverter valve [3 and conduit 23. Heat from the steam is transmitted through the tubes i8 to expel refrigerant vapor from absorption solution therein and the vapor rises upwardly through the tubes at considerable velocity and raises the absorption solution at the sides of the tubes by a climbing film vapor lift action. The refrigerant vapor flows from the separating chamber 20 to the condenser l through a conduit 24 and the liquefied refrigerant flows from the condenser through a U-shaped conduit 25, or any other suitable means for maintaining the difference in pressure, to the evaporator or cooling element 9. Refrigerant vapor flows from the evaporator 9 through passages or headers 26 to the absorber I6.

Absorption solution weak in refrigerant or, in other words, a concentrated salt solution flows by gravity from the separating chamber 20 to the top of the absorber 15 in a path of fiow in-- cluding the conduit 21, heat exchanger [1 and conduit 28. The solution in the absorber IB absorbs refrigerant vapor and this solution strong in refrigerant or, in other words, dilute salt solution flows by gravity from the bottom of the absorber Hi to the inlet chamber 19 at the bottom of the generator II in a path of flow including the conduit 29, heat exchanger l1 and conduit 30. The absorption of refrigerant vapor in the absorber l6 maintains a relatively low pressure in the evaporator 9 so that the refrigerant evaporates at a low temperature to produce a refrigerating effect and the low pressure in the evaporator and absorber is maintained by liquid columns in conduits 25, 28 and 25.

The absorber l6 and condenser 15 are cooled by cooling water from any suitable source such as the cooling tower 3| illustrated in Fig. 1 of the drawings. An electric motor driven fan 32 produces a flow of air upwardly through the cooling tower 3| and an electric motor driven pump 33 at the bottom of the tower circulates cooled water through the absorber l5 and condenser I5 of the refrigeration system. The path of flow of the cooling water includes the conduit 34, cooling coils 35 in the absorber l5, conduit 36, condenser I5 and conduit 31 back to the top of the cooling tower.

The heating system comprises the radiator l0 and a conduit 38 connecting the diverter valve l3 to the radiator.

The boiler l2 may be heated by any suitable type of fluid fuel burners, such as the plurality of gas burners 39, 40 and M illustrated in Fig. l.

. The flow of fuel to the burners 39, 40 and 4! is preferably controlled by a. master valve 42 in the fuel supply line 43 and operated by an electric motor 44 and by individual magnetically operated control valves. For purpose of description it will be considered that the supply of fuel to all of the burners 39, 40 and 4| is controlled by the valve 42. As more heat may be required by the heating system to heat the air than is required by the refrigeration system to cool the air, an adjustable gas pressure regulator 45 may be provided in the fuel supply line 43.

Steam generated in the boiler 12 is delivered through the steam main l2a to the diverter valve I! where it is delivered to either the heating system or the heat operated refrigeration system. As illustrated most clearly in Fig. 2 the diverter valve l3 comprises a valve body constituting a steam chamber 45 and a valve head 41 mounted on a crank arm 48 to adapt it to cooperate with a valve port 49 connected to the conduit 38 or with a valve port 50 connected to the conduit 23. The crank arm 48 is mounted fast on a shaft 5| having a crank arm 52 at the outside of the casing. The valve head 41 may be shifted manually by actuating the crank arm 52 but a illustrated the crank arm 52 is connected to a motor 53 through a link 54. Rotation of the motor 53 through half a revolution moves the valve head 41 through an angle ofto close one port 49 or 50 and open the other port. Motion is also transmitted from the motor 53 through a Boden wire drive 55 to adjust the gas pressure regulator 45 simultaneously with adjustment of the diverter valve I3 for a heating or cooling operation, respectively.

Thus, with the diverter valve head 41 in the position illustrated in Fig. 2 all of the steam generated in the boiler I2 is delivered through the conduit 23 to the generator H of the refrigeration system. When the valve head 41 is moved into engagement with the port 50 all of the steam is delivered through the conduit 38 to the heating element It). Condensate from the heating chamber 22 of the generator I4 is returned by a condensate pump 56 to a connection 51 at the side of the boiler I2. Condensate from the heating radiator l0 flows back through the conduit 38 to the chamber 46 of the diverter valve l3 and through a drain tube 58 to the boiler l2. Make-up water is supplied to the boiler l2 through a supply pipe controlled by an electro-magnetically operated valve 59 and a float operated switch 59a. The operation of the various elements of the air conditioning apparatus is regulated by suitable control means such as the electric control circuits illustrated in U. S. Patent No. 2,486,908, referred to above, and which may be considered as incorporated herein. As thus far described the air conditioning apparatus is substantially identical with that illustrated in said Andersson application.

In accordance with the present invention a novel arrangement is provided for directing steam from said boiler I2 to both the refrigeration system and heating system simultaneously to dehumidify the air by cooling and reheat the de humidified air. The reheat arrangement comprises a path of flow separate from the normal path for delivering steam to the heating system together with a flow controlling valve means in the separate path. In the illustrated embodiment the separate path comprises a by-pass conduit 88 connecting the chamber 48 of thediverter valve 13 .to the conduit 38 at a point beyond the valve seat 49. As shown in detail in Fig. 2' the lower end of the conduit 38 comprises. an elbow 6|, a-

rearwardly extending pipe section 82 and a laterally extending pipe section 83 connected to the valve seat 49. While the .by-pass conduit 60 may take other forms, it is shown connected between the top of the valve chamber 48 and the bottom of the elbow 8| for a reason. as'will later appear.

The by-pass conduit 60 may-have such a crosssectional area relative to the cross-sectional area of the conduit 23 as to produce the desired division of steam between the refrigeration system and heating system to dehumidify the air by cooling and reheat the dehumidified air to substantially the same temperature at which it enters the conditioning chamber. As shown in Fig. 2 the by-pass conduit 80 is made larger than necessary to deliver the desired amount of steam to th heating element or radiator l and a measuring orifice 64 is provided in the conduit for passing the predetermined quantity of steam necessary to reheat the dehumidified air to its initial temperature.

The valve means in the by-pass conduit 80 also may take other forms but preferably comprises a liquid trap for opening or closing the conduit. The liquid trap is formed by a U-shaped portion 85 of the by-pass conduit 60 depending from the end 680. connected to the elbow 6| of the conduit 38. The end 68a of the by-pass conduit 80 is positioned directly under the downwardly directed portion of the conduit 38 to adapt it to receive all condensate returning from the heating element or radiator ID. A drain tube 66 connects the bottom of the trap 85 to the boiler connection 51, see Fig. 1, and the opening or closing of the by-pass conduit 60 by condensate in the liquid trap is controlled by a valve 81 in the drain tube. When the valve 6'! is closed, as illustrated in Fig. 2, condensate from the heating element 18 accumulates in the depending U-shaped portion 65 of the by-pass conduit 68 until it closes the conduit.

When the valve is open as illustrated in Fig. 3-

the condensate drains from the liquid trap 65 to open the by-pass conduit 88 and permits the fiow of steam to the heating element l0.

Valve 61 may be of any suitable type for closing the drain tube 68 and in the illustrated embodiment comprises a self-contained unit including a spring 88 for closing the valve and an electromagnet coil 69 for opening the valve. Coil '89 is connected in an electric control circuit including a thermostat 18 and a humidistate H connected for joint operation to open the valve when the temperature is below a predetermined value and the humidity is above a predetermined value. The control circuit illustrated regulates only the refrigeration system and valve means in the bypass conduit 60 but it will be understood that a control circuit would be provided for regulating the complete air conditioning apparatus. Sufiice it to state herein that such a control circuit may comprise a two position reversing switch 12 on the thermostat 70 adapted for operation manually, see Fig. 1, or automatically for energizing the motor 53 to select the heating system or refrigeration system for operation and connect branch circuits for energization by the thermostat to regulate the operation of the selected system.

The portion of the control circuit for regulating the refrigeration system and reheat arrangement comprises a conductor I8 from the selective switch 12,-:see- Fig- 2, a branch conductor-14..

connected to a movable contact 15 of the humidistat. H and including a relay switch 18. The humidistat II constructed and arranged as to actuate the movable contact 15 to open position when the humidity is low as illustrated in Fig. 2; and engage the movable contact. with a fixed contact 1'! whenthe humidity is high as illustratedin Fig. 3. Fixed contact 11 is connected to one 'side of the electro-magnet coil 69 by conductor I8.

and the opposite side of the-coil is connected to a return conductor 19. A second branch from a the conductor 13 comprises a conductor 88 con-... nected to a movable contact 8| of the thermostat: 18. When the air in the enclosure is above a predetermined temperature a thermal responsive element 82 moves the contact 8| into engagementwith fixed contact 83 :connected by a conductor 84 to the electric motor 44 for operating the fuel valve 42. The opposite side of the motor 44 is connected to the return conductor 18. A conduc-- tor 85 also connects conductor 8| to a second"- switch contact 8: of thermostat 18 to simultaneously complete a circuit through a relay coil 86 for switch 18 connected in parallel with thevalve motor 44. The circuit for the relay coil 86 is completed from the switch contact 8la to one side of the coil and from the other sideofthe coil to the return 19 by a conductor 81. A third branch from conductor 13 comprises a'conductor 88, a relay switch 89 and a conductor 98 to con-. ductor 85 and movable switchcontact 8la of the thermostat 10. Switch 88 .is normally biased to open position and actuated. to closed position by a relay coil 9| connected between fixed contact 11 of the humidistat H and return conductor [8 and in parallel with-the electro-magnet coil 88 for actuating the valve .81. One form of the invention having now been described in detail the mode of operation is explained as follows.

When the enclosure 5 is to be heated the diverter valve I3. is actuated either manually orand close the by-pass conduit. When condensate automatically to engage the valve headll' with the valve seat 58=and thereby close the conduit 23 i to the generator 14 and open 'the conduit 38 to I the heating-element or radiator 10. The motor 44 is then energized to open fuel valve 42 and supply fuel to the burners 39, 48 and 4| to heat the boiler 1 I2 andgenerate steam therein. Steam generated in the b0iler*l2 flows through the steam main-- l2a to the chamber 16 of the diverter valve I8 and through the port 49 and conduit 38 to the radiator l8. Some of the steam may flow through the by-pass conduit 88 at the beginning of a" heating operation but condensate draining fromthe radiator III will soon-fill the liquid trap 65 in trap rises to the-level of the rearwardly extending portion 62 of conduit 38 it will overflow into the valve-chamber 48 and flow back to the boiler 12 through the drain conduit 58. =When' steam is supplied to the heating element or'radi-"- ator ID the fan I is operated to draw air from the enclosure 5.through the duct! where it is filtered by the filter 8, heated by the radiator l8, humidified by the humidifier l I and then returned to the enclosure through the duct 6.- Preferably." the operation of the motor 44 for the fuel valve 42 and fan 1' is regulated automatically by a suitable control to maintain the air in the enclosure at a predetermined temperature. 8 When the enclosure is to be cooled the'diverter valve head 41 is shifted-either manually orautomatically, to the position illustrated in Fig.2 to J close port 49 to the heating element l and open port 50 to the generator l4 of the refrigeration system. Upon an increase in temperature in the enclosure 5. the thermal element 82 of the thermostat 10 will actuate the movable contacts 8| and Ma into engagement with the fixed contacts 83 and 83a to complete a circuit through conductors l3 and 80. switch contacts 8| and 83 to energize the motor 44 and open the fuel valve 42. With i'uel supplied to the burners 39, 40 and 41 the boiler 62 is heated to generate steam therein. Simultaneously, a circuit is completed from conductor 84 through conductor 85, switch contacts 83a and Bio, relay coil 86 and conductors 81 and 19 to open relay switch 16, deenergize electromagnet coil 69 and close valve 61, if open, under the action of spring 68, see Fig. 2.

Steam generated in the boiler 12 is delivered through the main [2a, diverter valve l3 and conduit 23 to the generator N. If the by-pass conduit 60 is open at the beginning of a cooling operation steam also will flow therethrough. However, after a short period of time condensate from the heating element Ill will hill the liquid trap 65 and close the conduit. The steam supplied to the generator l4 ,will operate the refrigeration system to supply refrigerant to the evaporator 9 in the manner previously explained. When steam is delivered to the generator 14, operation of the blower l is initiated which draws air from the enclosure 5 and through the duct 4 where it is filtered by the filter 8, cooled by the cooling element 9 and then returned to the enclosure through the duct 6. A portion of the air directly contacting the evaporator 9 will be cooled below its dew point to remove moisture and thereby dehumidify as well as cool the air. The refrigeration system continues to operate until the temperature in the enclosure falls to the degree desired at which time the thermal element 82 of the thermostat 10 opens switch contacts BI and 8 la to deenergize fuel valve motor 44 and terminate a cooling cycle of operation. The refrigeration system is operated intermittently as regulated by the thermostat 10 to maintain the enclosure at the desired temperature.

When the humidity iii the enclosure 5 is high and the temperature is satisfactory, both the refrigeration system and heating system are operated simultaneously to dehumidify the air by cooling and reheat the dehumidified air. Under such conditions the thermostatic switches BI and Ma are open and the relay switch 16, humidity responsive switch and relay switch 89 are closed as illustrated in Fig. 3. A circuit is then completed through conductors T3 and 14, relay switch 16. humidity responsive switch contacts 15 and TI and then through the electro-magnet coil 69 and relay coil 9| arranged in parallel to the return conductor 19. Energization of coil 69 opens drain valve 61 against the action .of spring 68. Condensate in the liquid trap 65 then flows by gravity through the drain tube 66 back to the boiler l2 and opens the by-pass conduit 60. The energization of the relay coil 9| closes relay switch 89 to complete a circuit from 13 through conductors 88, 90, 85, 84 and valve motor 44 to return conductor 19. Energization of motor 44 opens fuel valve 42 to generate steam in boiler l2. Open switch contact 8la prevents energization of relay coil 86.

Steam then flows from the boiler I! through the steam main 12a to the chamber 46 of the diverter valve l3 where its flow is divided between the conduit 23 to the generator H of the refrigeration system and the by-pass conduit 60 and conduit 38 to the radiator ID of the heating system. The blower I then draws air from the enclosure 5 through the duct 4 where it is successively cooled by the evaporator 9 and heated by the radiator III to dehumidify the air without substantially changing its temperature. The division of steam is accurately proportioned by the relative size of the valve port 50 and the orifice 64 in the by-pass conduit 60 to give the desired ratio of cooling and heating.

The apparatus continues to operate to dehumidify the air by cooling and reheat the dehumidified air until either the humidity decreases below a predetermined value or the temperature increases above a predetermined value. If the humidity decreases the humidity responsive switch H opens the circuit to the electromagnetic actuating coil 69 and valve 61 is closed by spring 68. Upon deenergization of relay coil 9! switch 89 opens to deenergize motor 44 to close the fuel valve 42 and thereby stop the operation of the refrigeration system. If the temperature in the enclosure 5 increases above a predetermined value the thermal element 82 closes switch contacts BI and Blu to complete a circuit through fuel valve motor 44 and relay coil 86 as previously explained. Energization of relay coil 86 opens relay switch 16 and deenergizes coil 69 which causes valve 61 to close under the action of spring 68. Condensate from the heating radiator l0 then closes by-pass conduit 60 and stops the reheating of the cooled air. Thus the apparatus operates to dehumidify the air by cooling and reheat the dehumidified air only when the temperature is below and the humidity is above permissible limits.

It will now be observed that the present invention provides a. novel arrangement in a heat operated air conditionin apparatus for cooling or heating the air or simultaneously dehumidiiying and reheating the air in an enclosure. It will also be observed that the present invention provides separate paths for directing heat from a source to the heating system with a novel valve arrangement for controllin the flow through said separate paths. It will still further be observed that the present invention provides an arrangement for dehumidifying the air in an enclosure hy cooling and reheating the dehumidified air only when the temperature is low and the humidity is high.

While only a single embodiment of the invention is illustrated and described, it will be understood that modifications may be made in the construction and arrangement of parts without departing from the spirit or scope of the invention.

Therefore, without limitation in this respect, the invention is defined by the following claims.

I claim:

1. Air conditioning apparatus comprisin a heating system having a heating element, a heat operated refrigeration system having a cooling element, a source of heating medium, conduit means including selective valve means providing separate paths for directing heating medium from said source to the heating system or to the heat operated refrigeration system, respectively, a conduit providing a second path for directing heating medium from said source to the heating element independently of the selective valve, and humidity controlled valve means controllin the flow of heating medium through said last named conduit for opening the second path to the heatassume 9 ing element when the humidity is high whereby to supply heating medium to both the refrigeration system and heating element simultaneously to dehumidify the air by cooling and reheat the dehumidifled air.

2. Air conditioning apparatus comprising a heating system having a heating element, a heat operated refrigeration system having acooling element, a source of heating medium, conduit means providing inidividual paths for directing heating medium from said source to the heating system or to the heat operated refrigeration system, respectively, selective valve means in the conduit means for closing one path and opening the other path, a conduit providing a second path for directing heating medium from said source to the heating element independently of the selective valve means, and humidity controlled valve means for controlling the flow of heating medium through said last named conduit to open the second .path when the first path is closed and the humidity is high to supply heating medium to both the refrigeration system and heating element simultaneously, said conduit being so constructed and arranged as to divide the heating medium between the refrigeration system and heating element to dehumidify the air by cooling and reheat the dehumidifled air to its initial temperature.

3. Air conditioning apparatus comprising a heating system having a heating element, a heat operated refrigeration system having a cooling element, a source of heating medium, means including a selective valve for directing heating medium from said source to the heating system or to the heat operated refrigeration system, respectively, a conduit for directing heating medium from said source to the heating element independently of the selective valve, valve means for controlling the flow of heating medium through said conduit to supply heating medium to both the refrigeration system and heating element simultaneously, and an orifice in said conduit to divide the flow of heating medium between the refrigeration system and heating element to dehumidify the air by cooling and reheatthe dehumidifled air.

4. Air conditioning apparatus comprising a heating system having a heating element, a heat operated refrigeration system having a cooling element, a source of heatin medium, a chamber connected to said source of heating medium, conduits connecting said chamber to the heating element and refrigeration system, respectively, a selective valve in said chamber shiftable from one to the other of two positions for closing one conduit and opening the other conduit, a conduit by-passing the selective valve to direct heating medium from the chamber to the heating element, and humidity responsive valve means for controlling the flow of heating medium through said by-pass conduit to open the latter.

when the humidity is high whereby to supply heat to both the refrigeration system and heating element simultaneously to dehumidify the air by cooling and reheat the dehumidified air.

5. Air conditioning apparatus comprising a heating system having a heating element, a heat operated refrigeration system having a cooling element, a source of heating medium, a chamber connected to said source of heating medium, conduits connecting said chamber to the heating system and refrigeration system, respectively, a selective valve in said chamber shiftable from one to the other of two positions for closing one conduit and opening the other conduit, a conduit by-passing the selective valve to direct heating medium from the chamber to the heating system, valve means for closing the bypass conduit, and a humidistat for actuating the valve means to open the conduit when the humidity is high whereby to supply heat to both the refrigeration system and heating system simultaneously to dehumidify the air by cooling and reheat the dehumidified air.

6. Air conditioning apparatus comprising a heating system having a heating element, a heat operated refrigeration system having a cooling element and a heat receiving element, a source of heating medium, means including a selective valve for directing heating medium from said source to the heating system or to the heat receiving element of" the refrigeration system, respectively, a conduit for directing heat from said source to the heating system independently of the selective valve means, a second valve means for closing the conduit, and control means including a thermostat and humidistat connected for jointoperation to actuate the valve means and open the conduit when the temperature is below a predetermined value and the humidity is above a predetermined value whereby to dehumidify the air by cooling and reheat the dehumidifled air.

7. Air conditioning apparatus comprising a heating system having a heating element, a heat operated refrigeration system having a cooling element and a heat receiving element, a source of steam, means including a selective valve for directing steam from said source to the heating system or heat receiving element of the refrigeration system, respectively, a conduit by-passing said selective valve for directing steam from said source to the heating element, valve means for closing the conduit, and humidity responsive control means for actuating the last named valve means to open the by-pass conduit when the selective valve is directing steam to the refrigeration system and the humidity is high to supply steam to the heating element and heat receiving element of the refrigeration system simultaneously whereby to dehumidify the air by cooling and reheat the dehumidlfled air.

8. Air conditioning apparatus comprising a heating system having a heating element, a heat operated refrigeration system having a cooling element and a heat receiving element, a steam boiler, a chamber connected to receive steam from said boiler, conduits connecting said chamber to the heating element and heat receiving element of the refrigeration system, respectively, selective valve means shiftable from one to the other of two positions for closing one conduit and opening the other conduit, a by-pass conduit connecting the chamber to the heating element around the selective valve means, a second valve means for closing the by-pass conduit, and control means including a thermostat and humidistat connected for Joint operation to actuate the valve means to open the by-pass conduit when the temperature is below a predetermined value and the humidity is above a predetermined value to supply heat to both the refrigeration system and heating system simultaneously whereby to dehumidify the air by cooling and reheat the dehumidified air.

9. Air conditioning apparatus comprising a heating element for heating air to be conditioned, a source of steam at substantially atmospheric pressure, a conduit connecting said source of steam to the heating element, a mechanical valve for closing the conduit, a by-pass conduit around system, a heating element for heating a for closing the drain to accumulate condensatein the trapand close the by-pass to prevent steam from flowing therethrough or open the drain to draw off condensate and open the conduit to permit steam to fiow therethrough.

10. Air conditioning apparatus comprising a heat operated refrigeration system having a cooling element for coolingthe air to be conditioned and a heat receiving element, a source of steam, a conduit for delivering steam from said source tothe heat receiving element of" the refrigeration to be conditioned, a conduit for delivering steam from said source to the heating element and arranged to receive condensate from the heating element, said conduit being formed to provide a liquid trap, a drain from the liquid trap, and control means for closing the drain to accumulate condensate in the liquid trap and close the conduit and open the drain to draw off condensate and open the conduit.

11. Air conditioning apparatus comprising a heating element, a heat operated refrigeration system having a cooling element, a source of steam, means for delivering steam from said source to the heating element or to the refrigeratioh system, respectively, a separate conduit connecting said source of heat to the heating element, and valve means in the conduit comprising a liquid trap, a drain from the liquid trap, and means for opening and closing the drain whereby to fill the liquid trap with condensate when the drain is closed to prevent the flow of steam to the heating element and draw of! condensate from the trap when the drain is open to permit the flow of steam to the heating element and refrigeration system simultaneously.

12. Air conditioning apparatus comprising a heating system having a heating element, a heat operated refrigeration system having a cooling element and a heat receiving element, a source of steam, a conduit for delivering steam from said source to the heating system, a conduit for delivering steam from said source to the heat receiving element of the refrigeration system, a selective valve for opening one conduit and closing-the other conduit, a by-pass conduit around said selective valve for delivering steam from said source to the heating system and arranged to receive condensate from the heating element, said by-pass conduit forming 9, liquid trap, a drain from said liquid trap, and a valve for closing the drain to fill the trap with condensate and prevent the flow of steam or opening the drain ing air to be conditioned, a conduit for delivering steam from said source to the heating element and arranged to receive -condensate from the heating element, said conduit being formed to provide a liquid trap, a drain from the liquid trap, and a humidistat for opening the drain when the humidity is above a predetermined value to draw off the condensate and open the conduit whereby to dehumidify the air by cooling and reheat the dehumidified air.

14. Air conditioning apparatus comprising a heat operated refrigeration system having. a cooling element for cooling the air to be conditioned and a heat receiving element, a source of steam, a conduit for delivering steam from said source to the heat receiving element of the refrigeration system, a heating element for heating air to be conditioned, a conduit for delivering steam from said source to the heating element and arranged to receive condensate from the heating element, said conduit being formed to provide a liquid trap for closing the conduit when filled with condensate, a drain from the liquid trap, a valve for closing the drain, an operating device for actuating the valve to open the drain, and an electric control circuit comprising a thermostat and humidistat connected to energize the operating device to open the valve when the temperature is below a predetermined value and the humidity is above a predetermine value.

15. Air conditioning apparatus comprising a heating system having a heating element, a heat operated refrigeration system having a cooling element and a heat receiving element, a source of steam, a conduit for delivering steam from said source to the heating system, a conduit -for delivering steam from said source to the heat receiving element of the refrigeration system, a selective valve for opening one conduit and closing the other conduit, a by-pass conduit around said selective valve for delivering steam from said source to the heating system and receiving condensate from the heating system, said conduit being formed to provide a liquid trap, a drain from the liquid trap, a valve for closing the drain, an operating device for actuating the valve to open the drain, and an electric control circuit comprising a thermostat and humidistat connected to'energize the operating device to open the valve when the temperature is below a predetermined value and the humidity is above a predetermined value whereby to dehumidify the air by cooling and reheat the dehumidified air.

LOWELL McNEELY..

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Andersson Nov. 1, 1949 

